title: Recyclable antibacterial magnetic nanoparticles grafted with quaternized poly(2-(dimethylamino)ethyl methacrylate) brushes.
abstract: Highly efficient recyclable antibacterial magnetite nanoparticles consisting of a magnetic Fe(3)O(4) core with an antibacterial poly(quaternary ammonium) (PQA) coating were prepared in an efficient four-step process. The synthetic pathway included: (1) preparation of Fe(3)O(4) nanoparticles via coprecipitation of Fe(2+)/Fe(3+) in the presence of an alkaline solution; (2) attachment of an ATRP initiating functionality to the surface of the nanoparticles; (3) surface-initiated atom transfer radical polymerization (ATRP) of 2-(dimethylamino)ethyl methacrylate (DMAEMA); and (4) transformation of PDMAEMA brushes to PQA via quaternization with ethyl bromide. The success of the surface functionalization was confirmed by FT-IR, thermal gravimetric analysis (TGA), elemental analysis, and transmission electron microscopy (TEM). The PQA-modified magnetite nanoparticles were dispersed in water and exhibited a response to an external magnetic field, making the nanoparticles easy to remove from water after antibacterial tests. The PQA-modified magnetite nanoparticles retained 100% biocidal efficiency against E. coli (10(5) to 10(6)E. coli/mg nanoparticles) during eight exposure/collect/recycle procedures without washing with any solvents or water.
authors.affiliation: Chemistry Department, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States.
authors.forename: Hongchen
authors.initials: H
authors.lastname: Dong
authors.forename: Jinyu
authors.initials: J
authors.lastname: Huang
authors.forename: Richard R
authors.initials: RR
authors.lastname: Koepsel
authors.forename: Penglin
authors.initials: P
authors.lastname: Ye
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Russell
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Matyjaszewski
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002850:Chromatography, Gel; D009682:Magnetic Resonance Spectroscopy; D008280:Magnetics; D008689:Methacrylates / Q000737:chemistry*; D053758:Nanoparticles; D009757:Nylons / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000900:Anti-Bacterial Agents; D008689:Methacrylates; D009757:Nylons; C407037:poly(2-(dimethylamino)ethyl methacrylate)